Access to and use of electronic documents is growing at a very explosive pace. To facilitate use of large collections of electronic documents, new techniques for querying and visualizing the content of such collections are being developed. For example, U.S. Pat. No. 5,546,529 describes a technique for viewing the results of a database search that has been mapped to a tree structure. The tree structure is visually mapped along a static reference surface having separate detail and context areas.
One source of the growth of access to electronic documents is the Internet, and in particular, the facet of the Internet known as the World-Wide-Web (referred to simply as the Web). The Web provides a means for making multi-media styled documents over the Internet. These documents are termed Web pages (hereinafter pages). Pages may refer to and provide access to other pages on the Web. Each page has associated with it an identifier termed a Uniform Resource Locator (URL). A page is accessed by specifying it's URL. The contents of a page is specified in a document formatting language known as the Hyper-Text Mark-Up Language (HTML). A reference to another page on the Web is termed a link. Links may be specified in either absolute or relative terms. A link specified in absolute terms refers to it's entire URL. A link specified in relative terms assumes a certain portion of the URL is the same as the existing page. The specification is thus relative to the URL of the page on which it is defined.
To access and view a document on the Web, a Web browser is needed. A Web browser provides search, traversal and viewing functions needed to access documents on the Web. Various Web browsers exist for the Web, e.g. NetScape available from NetScape, Inc. of Mountain View, California. Traversing through documents contained on the Web is similar to following a path through a network. Since each page may contain links to many other pages, traversing through the pages is a simple matter of following the links. Most Web browsers provide controls for going backwards and forwards in the list of links. They also maintain a history list of the links to enable jumping directly to a specific previously viewed page.
Most publicly available Web browsers operate on a computer controlled display system having a graphical user interface with multiple windows. Typically, such web browsers operate such that a window may display only one page at a time. Multiple pages are viewed by opening multiple windows. The user interface for Web Browsers typically correspond to the capabilities of the computer system on which it resides. A full featured Web browser may provide rendering means for viewing audio, video and graphical portions of documents as well as a graphical user interface for controlling access to documents. The graphical user interface is typically one which provides for vertical and horizontal scrolling via scroll bars and point and click manipulation of a cursor control device to invoke browser operations (e.g. to traverse links). Color, underlining or reverse video are techniques used to indicate the existence of a link on a page.
Related materials include:
Deckscape: An Experimental Web Browser, Marc H. Brown and Robert A. Shillner, DEC Systems Research Center Report 135a, Mar. 1, 1995. The DeckScape web browser utilizes the metaphor of a deck as a collection of Web pages. Only one Web page on a deck is visible at one time, although multiple decks may be visible. DeckScape is also multithreaded so that each deck may be "active", e.g. downloading pages, at the same time. A deck may be created based on a traversal through the Web or as the result of an operation such as "expand all the links on this page."
U.S. Pat. No. 5,499,330 entitled Document Display System For Organizing And Displaying Documents As Screen Objects Organized Along Strand Paths. As described in the Abstract, this references discloses a system for displaying documents in a computer controlled display device. "The system displays documents either in a completely free-form, a user controlled configuration or as strands, such that documents in a strand follow a strand path. The strand path is a two dimensional line through a three dimensional display space. The documents displayed on the strand are known as child documents, and each strand also has a parent document. Various constraints defining the strand are associated with the parent document, including a strand function defining the strand path, minimum and maximum separation constraints defining the distance between the child documents on the strand, and an origin constraint defining the positional relationship of the strand path to the screen object of the parent document."
A `Pile` Metaphor for Supporting Casual Organization of Information, Richard Mander, Gitta Saloman, Yin Yin Wong, Chi '92 Conference Proceedings, ACM Conference on Human Factors in Computing Systems, pgs 627-634, May 3-7, 1992. This article describes the design and development of a desktop interface element referred to as piles. Piles represent sets of related documents. These piles are analogous to stacks of paper often found in a persons office or workspace. Piles were observed to have the useful properties of being a less rigid categorization system and to be self-revealing and browsable. The described design includes direct manipulation techniques and support for browsing, automatic pile construction and reorganization.
Representation in Virtual Space: Visual Convention in the Graphical User Interface, Loretta Staples, Human Factors in Computing Systems INTERCHI'93 Conference Proceedings, pgs 348-354, Apr. 24-29 1993. This articles describes the use of three dimensional visual cues of perspective and lighting, in the context of flat or two-dimensional workspace. The use of transparency as a means of enhancing the workspace is also described. A desktop "landscape" is proposed that is divided by a horizon line denoting two separate areas: an active foreground space and a passive background space.